Three-dimensional semiconductor memory device

ABSTRACT

A three-dimensional (3D) semiconductor memory device that includes a peripheral logic structure including peripheral logic circuits disposed on a semiconductor substrate and a first insulation layer overlapping the peripheral logic circuits, and a plurality of memory blocks spaced apart from each other on the peripheral logic structure. At least one of the memory blocks includes a well plate electrode, a semiconductor layer in contact with a first surface of the well plate electrode, a stack structure including a plurality of electrodes vertically stacked on the semiconductor layer, and a plurality of vertical structures penetrating the stack structure and connected to the semiconductor layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of co-pending U.S. application Ser.No. 14/878,453 filed on Oct. 8, 2015, which claims priority under 35U.S.C. §119 to Korean Patent Application No. 10-2014-0146296, filed onOct. 27, 2014, in the Korean Intellectual Property Office, thedisclosures of which are incorporated by reference herein in theirentireties.

TECHNICAL FIELD

Exemplary embodiments of the inventive concept relate tothree-dimensional (3D) semiconductor memory devices.

DISCUSSION OF THE RELATED ART

Semiconductor devices are becoming more highly integrated to meetdemands of high performance and low costs. The integration density of asemiconductor device directly affects its cost. For example, anintegration degree of a two-dimensional (2D) or planar semiconductordevice is mainly determined by an area needed for a unit memory cell.Therefore, the integration density of the 2D or planar semiconductordevice depends on a technique used for fine pattern formation. Evenfiner patterns may be formed to increase the density of the 2D or planarsemiconductor device. However, extremely advanced and high-pricedequipment is needed to form the fine patterns. Accordingly,three-dimensional (3D) semiconductor memory devices includingthree-dimensionally arranged memory cells have been developed toincrease integration density.

SUMMARY

Exemplary embodiments of the inventive concepts providethree-dimensional (3D) semiconductor memory devices with increasedreliability and integration density.

In an exemplary embodiment of the inventive concept, a 3D semiconductormemory device may include: a peripheral logic structure includingperipheral logic circuits disposed on a semiconductor substrate and afirst insulation layer overlapping the peripheral logic circuits; and aplurality of memory blocks disposed on the peripheral logic structureand spaced apart from each other. At least one of the memory blocks mayinclude: a well plate electrode; a semiconductor layer in contact with afirst surface of the well plate electrode; a stack structure including aplurality of electrodes vertically stacked on the semiconductor layer;and a plurality of vertical structures penetrating the stack structureand connected to the semiconductor layer.

In an exemplary embodiment of the inventive concept, the stack structuremay extend in a first direction on the semiconductor layer. Thesemiconductor layer may include a common source region disposed at aside of the stack structure. The common source region may have dopantsof a first conductivity type.

In an exemplary embodiment of the inventive concept, the common sourceregion may be spaced apart from the well plate electrode.

In an exemplary embodiment of the inventive concept, the peripherallogic circuits may include a voltage generator disposed on thesemiconductor substrate, and the peripheral logic structure may furtherinclude: a first interconnection structure for electrically connectingthe well plate electrode to the voltage generator.

In an exemplary embodiment of the inventive concept, the peripherallogic circuits may include a page buffer and a voltage generator thatare disposed on the semiconductor substrate. The peripheral logicstructure may further include: a plurality of first interconnectionselectrically connected to the page buffer; and a second interconnectionelectrically connected to the voltage generator. The secondinterconnection may be electrically connected to the well plateelectrode.

In an exemplary embodiment of the inventive concept, the secondinterconnection may include a plurality of second interconnections. Thesecond interconnections and the first interconnections may be disposedat the same level from a first surface of the semiconductor substrate,and the plurality of first interconnections may be arranged between thesecond interconnections spaced apart from each other.

In an exemplary embodiment of the inventive concept, the at least onememory block may further include: a plurality of third interconnectionsextending in parallel to each other on the stack structure. The thirdinterconnections may be electrically connected to the firstinterconnections.

In an exemplary embodiment of the inventive concept, the semiconductorlayer may have dopants of a second conductivity type. The semiconductorlayer may include: a first portion in contact with the well plateelectrode; and a second portion on the first portion. A concentration ofthe dopants of the second conductivity type in the first portion may behigher than a concentration of the dopants of the second conductivitytype in the second portion.

In an exemplary embodiment of the inventive concept, the semiconductorlayer may include a well dopant region that has a second conductivitytype and is in contact with the well plate electrode.

In an exemplary embodiment of the inventive concept, the well plateelectrode of the at least one memory block and a well plate electrode ofanother memory block may be spaced apart from each other on the firstinsulation layer.

In an exemplary embodiment of the inventive concept, an area of the wellplate electrode may be substantially equal to an area of thesemiconductor layer.

In an exemplary embodiment of the inventive concept, the 3Dsemiconductor memory device may further include: a data storage layerdisposed between the stack structure and each of the verticalstructures.

In an exemplary embodiment of the inventive concept, a 3D semiconductormemory device may include: a well plate electrode; a semiconductor layeroverlapping a first surface of the well plate electrode; a plurality ofstack structures extending in parallel to each other along a firstdirection on the semiconductor layer, first and second stack structuresof the stack structures comprising a plurality of electrodes verticallystacked on the semiconductor layer; vertical structures penetrating thefirst and second stack structures and connected to the semiconductorlayer; and common source regions formed in the semiconductor layerbetween the first and second stack structures, the common source regionshaving dopants of a first conductivity type.

In an exemplary embodiment of the inventive concept, the common sourceregions may be spaced apart from the first surface of the well plateelectrode.

In an exemplary embodiment of the inventive concept, the semiconductorlayer may include a well dopant region that has a second conductivitytype and is in contact with the well plate electrode.

In an exemplary embodiment of the inventive concept, the semiconductorlayer may have dopants of a second conductivity type. The semiconductorlayer may include: a first portion in contact with the well plateelectrode; and a second portion on the first portion. A concentration ofthe dopants of the second conductivity type in the first portion may behigher than a concentration of the dopants of the second conductivitytype in the second portion.

In an exemplary embodiment of the inventive concept, an area of the wellplate electrode may be substantially equal to an area of thesemiconductor layer.

In an exemplary embodiment of the inventive concept, the 3Dsemiconductor memory device may further include: a peripheral logicstructure including peripheral logic circuits formed on a semiconductorsubstrate and a first insulation layer overlapping the peripheral logiccircuits. The well plate electrode may be disposed on the firstinsulation layer.

In an exemplary embodiment of the inventive concept, the peripherallogic circuits may include a voltage generator disposed on thesemiconductor substrate and electrically connected to the well plateelectrode. A vertical distance between the voltage generator and thewell plate electrode may be smaller than vertical heights of the firstand second stack structures.

In an exemplary embodiment of the inventive concept, the 3Dsemiconductor memory device may further include: a data storage layerdisposed between the first and second stack structures and each of thevertical structures.

In an exemplary embodiment of the inventive concept, a 3D semiconductormemory device may include: a first logic circuit disposed on asemiconductor substrate; an insulating layer disposed on the at leastone logic circuit and the semiconductor substrate; a well plateelectrode disposed on the insulating layer and overlapping the firstlogic circuit; and a semiconductor layer disposed between the well plateelectrode and a plurality of vertically stacked electrodes.

In an exemplary embodiment of the inventive concept, the well plateelectrode may be in direct contact with a first surface of thesemiconductor layer.

In an exemplary embodiment of the inventive concept, an entire firstsurface of the semiconductor layer may be in direct contact with thewell plate electrode.

In an exemplary embodiment of the inventive concept, the first logiccircuit may be a voltage generator or a page buffer.

In an exemplary embodiment of the inventive concept, the well plateelectrode, the semiconductor layer and the vertically stacked electrodesmay form a cell array structure.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features of the inventive concept will become moreapparent by describing in detail exemplary embodiments thereof withreference to the attached drawings, in which:

FIG. 1 is a block diagram illustrating a three-dimensional (3D)semiconductor memory device according to an exemplary embodiment of theinventive concept;

FIG. 2 is a perspective view illustrating a 3D semiconductor memorydevice according to an exemplary embodiment of the inventive concept;

FIG. 3 is a circuit diagram illustrating a cell array of a 3Dsemiconductor memory device according to an exemplary embodiment of theinventive concept;

FIGS. 4 and 5 are plan views each illustrating a 3D semiconductor memorydevice according to an exemplary embodiment of the inventive concept;

FIG. 6 is a plan view illustrating a 3D semiconductor memory deviceaccording to an exemplary embodiment of the inventive concept;

FIG. 7 is a cross-sectional view illustrating a 3D semiconductor memorydevice according to an exemplary embodiment of the inventive concept;

FIGS. 8 and 9 are diagrams each illustrating an arrangement ofperipheral logic circuits in a 3D semiconductor memory device accordingto an exemplary embodiment of the inventive concept;

FIG. 10 is a perspective view illustrating a 3D semiconductor memorydevice according to an exemplary embodiment of the inventive concept;

FIG. 11 is a plan view illustrating a portion of a 3D semiconductormemory device according to an exemplary embodiment of the inventiveconcept;

FIGS. 12, 13, and 14 are cross-sectional views respectively taken alonglines I-I′, II-II′, and III-III′ of FIG. 11 to illustrate a portion of a3D semiconductor memory device according to an exemplary embodiment ofthe inventive concept;

FIGS. 15A, 15B, 15C, and 15D are enlarged views of a portion ‘A’ of FIG.12, according to an exemplary embodiment of the inventive concept;

FIGS. 16A and 16B are enlarged views of a portion ‘B’ of FIG. 13,according to an exemplary embodiment of the inventive concept;

FIGS. 17A, 17B, and 17C are perspective views each illustratingperipheral logic structures of 3D semiconductor memory device accordingto an exemplary embodiment of the inventive concept;

FIGS. 18A and 18B each illustrate a well plate electrode included in a3D semiconductor memory device according to an exemplary embodiment ofthe inventive concept;

FIGS. 19 and 20 are cross-sectional views respectively taken along linesI-I′ and II-II′ of FIG. 11 to illustrate a 3D semiconductor memorydevice according to an exemplary embodiment of the inventive concept;

FIG. 21 is an enlarged view of a portion ‘B’ of FIG. 20, according to anexemplary embodiment of the inventive concept;

FIG. 22 is a view illustrating an erasing operation of a 3Dsemiconductor memory device according to an exemplary embodiment of theinventive concept;

FIG. 23 is a block diagram illustrating an electronic system including a3D semiconductor memory device according to an exemplary embodiments ofthe inventive concept;

FIG. 24 is a block diagram illustrating a memory card including a 3Dsemiconductor memory device according to an exemplary embodiment of theinventive concept; and

FIG. 25 is a block diagram illustrating an information processing systemincluding a 3D semiconductor memory device according to an exemplaryembodiment of the inventive concept.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Exemplary embodiments of the inventive concept will now be describedmore fully hereinafter with reference to the accompanying drawings. Theinventive concept, however, may be embodied in various forms and shouldnot be construed as being limited to only the illustrated embodiments.In the drawings, the sizes and relative sizes of layers and regions maybe exaggerated for clarity.

As used herein, the singular terms “a,” “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be understood that when an element is referred to asbeing “connected” or “coupled” to another element, it may be directlyconnected or coupled to the other element or intervening elements may bepresent.

It will be understood that when an element such as a layer, region orsubstrate is referred to as being “on” another element, it can bedirectly on the other element or intervening elements may be present.

The same reference numerals or the same reference designators may denotethe same elements throughout the specification.

Moreover, exemplary embodiments of the inventive concept are describedherein with reference to cross-sectional illustrations and/or planeillustrations that are idealized examples. Accordingly, variations fromthe shapes of the illustrations as a result, for example, ofmanufacturing techniques and/or tolerances, are to be expected. Thus,exemplary embodiments of the inventive concept should not be construedas limited to the shapes of regions illustrated herein but are toinclude deviations in shapes that result, for example, frommanufacturing. For example, an etching region illustrated as a rectanglewill, typically, have rounded or curved features. Thus, the regionsillustrated in the figures are schematic in nature and their shapes arenot intended to illustrate the actual shape of a region of a device andare not intended to limit the scope of the inventive concept.

Further, devices and methods of forming devices according to exemplaryembodiments of the inventive concept described herein may be embodied inmicroelectronic devices such as integrated circuits. In this case, aplurality of devices according to exemplary embodiments of the inventiveconcept described herein may be integrated in the same microelectronicdevice. Accordingly, the cross-sectional view(s) illustrated herein maybe replicated in two different directions, which need not be orthogonal,in the microelectronic device. Thus, a plan view of the microelectronicdevice that embodies devices according to exemplary embodiments of theinventive concept described herein may include a plurality of thedevices in an array and/or in a two-dimensional pattern depending on thefunctionality of the microelectronic device.

The devices according to exemplary embodiments of the inventive conceptdescribed herein may be interspersed among other devices depending onthe functionality of the microelectronic device. Moreover,microelectronic devices according to exemplary embodiments of theinventive concept described herein may be replicated in a thirddirection that may be orthogonal to the two different directions, toprovide three-dimensional integrated circuits.

Accordingly, the cross-sectional view(s) illustrated herein providesupport for a plurality of devices according to exemplary embodiments ofthe inventive concept described herein that extend along two differentdirections in a plan view and/or in three different directions in aperspective view. For example, when a single active region isillustrated in a cross-sectional view of a device/structure, thedevice/structure may include a plurality of active regions andtransistor structures (or memory cell structures, gate structures, etc.)thereon, as would be illustrated by a plan view of the device/structure.

FIG. 1 is a block diagram illustrating a three-dimensional (3D)semiconductor memory device according to an exemplary embodiment of theinventive concept.

Referring to FIG. 1, the 3D semiconductor memory device may include amemory cell array 1, a row decoder 2, a page buffer 3, a column decoder4, and control circuits 5.

The memory cell array 1 may include a plurality of memory blocks BLK0 toBLKn. Each of the memory blocks BLK0 to BLKn may include a plurality ofmemory cells, a plurality of word lines, and a plurality of bit lines.The word lines and the bit lines may be electrically connected to thememory cells.

The row decoder 2 may decode an address signal inputted from an externalsystem to select one of the word lines. The address signal decoded bythe row decoder 2 may be provided to a row driver. The row driver mayprovide word line voltages generated from a voltage generation circuitto the selected word line and unselected word lines in response to acontrol signal of the control circuits 5. The row decoder 2 may beconnected in common to the plurality of memory blocks BLK0 to BLKn andmay provide driving signals to the word lines of a memory block selectedby a block selection signal.

The page buffer 3 may be connected to the memory cell array 1 throughthe bit lines to read data stored in the memory cells. The page buffer 3may be connected to a selected bit line in response to an address signaldecoded by the column decoder 4. According to an operation mode, thepage buffer 3 may temporarily store data to be stored in the memorycells or may sense data stored in the memory cells. For example, thepage buffer 3 may be operated as a write driver during a programoperation mode and may be operated as a sense amplifier during a readoperation mode. The page buffer 3 may receive a power (e.g., a voltageor a current) from the control circuits 5 and may provide the receivedpower to the selected bit line.

The column decoder 4 may provide a data-transmitting path between thepage buffer 3 and an external device (e.g., a memory controller). Thecolumn decoder 4 may decode an inputted address signal to select one ofthe bit lines. The column decoder 4 may be connected in common to theplurality of memory blocks BLK0 to BLKn and may provide data to the bitlines of the memory block selected by the block selection signal.

The control circuits 5 may control overall operations of the 3Dsemiconductor memory device. The control circuits 5 may receive controlsignals and an external voltage and may be operated in response to thereceived control signals. The control circuits 5 may include a voltagegenerator that generates voltages (e.g., a program voltage, a readvoltage, and an erase voltage) used for internal operations by way ofthe external voltage. The control circuits 5 may control a readoperation, a write operation, and/or an erase operation in response tothe control signals.

FIG. 2 is a perspective view illustrating a 3D semiconductor memorydevice according to an exemplary embodiment of the inventive concept.

Referring to FIG. 2, the 3D semiconductor memory device may include aperipheral logic structure PS and a cell array structure CS. The cellarray structure CS may be stacked on the peripheral logic structure PS.In other words, the cell array structure CS may overlap the peripherallogic structure PS when viewed from a plan view.

In an exemplary embodiment of the inventive concept, the peripherallogic structure PS may include the row and column decoders 2 and 4, thepage buffer 3 and the control circuits 5 which are described withreference to FIG. 1. The cell array structure CS may include a pluralityof memory blocks BLK0 to BLKn. Each of the memory blocks BLK0 to BLKnmay correspond to a data-erasing unit. The memory blocks BLK0 to BLKnmay include structures stacked on a plane extending in first and seconddirections D1 and D2. The structures may be stacked along a thirddirection D3 on the plane. Each of the memory blocks BLK0 to BLKn mayinclude a cell array having a 3D structure (or a vertical structure).The cell array may include a plurality of three-dimensionally arrangedmemory cells, a plurality of word lines, and a plurality of bit lines.The word lines and the bit lines may be connected to thethree-dimensionally arranged memory cells.

FIG. 3 is a circuit diagram illustrating a cell array of a 3Dsemiconductor memory device according to an exemplary embodiment of theinventive concept.

Referring to FIG. 3, the cell array may include a common source lineCSL, a plurality of bit lines BL, and a plurality of cell strings CSTRdisposed between the common source line CSL and the bit lines BL.

The bit lines BL may be two-dimensionally arranged. A plurality of thecell strings CSTR may be connected in parallel to each of the bit linesBL. The cell strings CSTR may be connected in common to the commonsource line CSL. In other words, a plurality of the cell strings CSTRmay be disposed between a common source line CSL and the plurality ofbit lines BL. In an exemplary embodiment of the inventive concept, thecommon source line CSL may be provided in plural, and the plurality ofcommon source lines CSL may be two-dimensionally arranged. The samevoltage may be applied to the plurality of the common source lines CSL.Additionally, the plurality of common source lines CSL may beelectrically controlled independently of each other.

Each of the cell strings CSTR may include a ground selection transistorGST connected to the common source line CSL, a string selectiontransistor SST connected to the bit line BL, and a plurality of memorycell transistors MCT interposed between the ground and string selectiontransistors GST and SST. The ground selection transistor GST, the memorycell transistors MCT and the string selection transistor SST may beconnected in series to each other.

The common source line CSL may be connected in common to sources of theground selection transistors GST. A ground selection line GSL, aplurality of word lines WL0 to WL3 and a string selection line SSL whichare disposed between the common source line CSL and the bit lines BL maybe used as gate electrodes of the ground selection transistor GST, thememory cell transistors MCT and the string selection transistor SST,respectively. The ground selection line GSL and the string selectionline SSL may be provided in plural. Each of the memory cell transistorsMCT may include a data storage element.

FIGS. 4 and 5 are plan views each illustrating a 3D semiconductor memorydevice according to an exemplary embodiment of the inventive concept.

Referring to FIGS. 4 and 5, row and column decoders 2 and 4, the pagebuffer 3, and control circuits 5 which constitute the peripheral logicstructure (PS of FIG. 2) may be disposed on a semiconductor substrate10. According to an exemplary embodiment of the inventive concept, thecell array structure (CS of FIG. 2) including a cell array 1 (CAR) maybe disposed on the page buffer 3 and the control circuits 5. Forexample, as illustrated in FIG. 4, the page buffer 3 and the controlcircuits 5 may overlap the cell array 1, and the row and column decoders2 and 4 may be disposed around the cell array 1 when viewed from a planview. In an exemplary embodiment of the inventive concept, asillustrated in FIG. 5, the column decoder 4, the page buffer 3, and thecontrol circuits 5 may overlap the cell array 1 when viewed from a planview. In this case, the row decoders 2 may be disposed around the cellarray 1 when viewed from a plan view.

FIG. 6 is a plan view illustrating a 3D semiconductor memory deviceaccording to an exemplary embodiment of the inventive concept. FIG. 7 isa cross-sectional view illustrating a 3D semiconductor memory deviceaccording to an exemplary embodiment of the inventive concept. FIGS. 8and 9 are diagrams each illustrating an arrangement of peripheral logiccircuits in a 3D semiconductor memory device according to an exemplaryembodiment of the inventive concept.

Referring to FIGS. 6 and 7, the peripheral logic structure PS and thecell array structure CS may be sequentially stacked on the semiconductorsubstrate 10. In other words, the peripheral logic structure PS may bedisposed between the semiconductor substrate 10 and the cell arraystructure CS in a vertical view. The peripheral logic structure PS andthe cell array structure CS may overlap each other in a plan view.

In an exemplary embodiment of the inventive concept, the semiconductorsubstrate 10 may be a silicon substrate, a silicon-germanium substrate,a germanium substrate, or a single-crystalline epitaxial layer grown ona single-crystalline silicon substrate.

According to an exemplary embodiment of the inventive concept, theperipheral logic structure PS may include peripheral logic circuitsintegrated on the semiconductor substrate 10 and a lower insulationlayer 50 covering the peripheral logic circuits. For example, theperipheral logic circuits may include the row and column decoders 2 and4, the page buffer 3 and the control circuits 5 described with referenceto FIGS. 1 and 4. According to an exemplary embodiment of the inventiveconcept, a page buffer 20 and a voltage generator 30 may be disposedunder the cell array structure CS and may be electrically connected tothe cell array structure CS.

In an exemplary embodiment of the inventive concept, the cell arraystructure CS may be stacked on the peripheral logic structure PS and mayinclude a plurality of memory blocks BLK1 and BLK2. Each of the memoryblocks BLK1 and BLK2 may include a well plate electrode 60, asemiconductor layer 70, and a stack structure ST.

The well plate electrode 60 may be disposed on the peripheral logicstructure PS and may have a plate shape. The well plate electrode 60 maybe disposed on a top surface of the lower insulation layer 50. In anexemplary embodiment of the inventive concept, the well plate electrodes60 of the memory blocks BLK1 and BLK2 may be spaced apart from eachother. The well plate electrode 60 may be electrically connected to thevoltage generator 30 of the peripheral logic structure PS. The wellplate electrode 60 may include a metal (e.g., tungsten, copper, oraluminum), a conductive metal nitride (e.g., titanium nitride ortantalum nitride), a transition metal (e.g., titanium or tantalum),and/or a metal silicide layer. According to an exemplary embodiment ofthe inventive concept, an erase voltage generated by the voltagegenerator 30 may be applied to the well plate electrode 60 during anerase operation of the 3D semiconductor memory device.

The semiconductor layer 70 may be in direct contact with a top surfaceof the well plate electrode 60 and may cover an entire top surface ofthe well plate electrode 60. The semiconductor layer 70 may includesilicon (Si), germanium (Ge), or a mixture thereof. The semiconductorlayer 70 may be formed of a semiconductor material doped with dopantshaving a first conductivity type or an intrinsic semiconductor materialnot doped with dopants. In addition, the semiconductor layer 70 may havea single-crystalline structure, an amorphous structure, or apoly-crystalline structure.

The stack structure ST may include electrodes EL sequentially stacked onthe semiconductor layer 70. The electrodes EL may form memory cells.Each of the electrodes EL may be formed of a conductive material (e.g.,doped silicon or a metal) and may have a line shape or a plate shape.

According to an exemplary embodiment of the inventive concept, asillustrated in FIG. 8, the page buffer 20 may be disposed under each ofthe memory blocks BLK1 and BLK2 and the voltage generator 30 may bedisposed under a plurality of the memory blocks BLK1 and BLK2. Inaddition, a row decoder 15 may be disposed at a side of the memoryblocks BLK1 and BLK2 when viewed from a plan view. According to anexemplary embodiment of the inventive concept, as illustrated in FIG. 9,the page buffer 20 and the voltage generator 30 may be disposed undereach of the memory blocks BLK1 and BLK2 when viewed from a plan view. Inaddition, the row decoders 15 may be disposed at sides of the memoryblocks BLK1 and BLK2 and between the memory blocks BLK1 and BLK2. In anexemplary embodiment of the inventive concept, the voltage generator 30may generate voltages (e.g., a program voltage, a read voltage, and anerase voltage) used for internal operations of the 3D semiconductormemory device. The voltage generator 30 may provide the generated erasevoltage to the well plate electrode 60 of a selected one of the memoryblocks BLK1 and BLK2.

FIG. 10 is a perspective view illustrating a 3D semiconductor memorydevice according to an exemplary embodiment of the inventive concept.FIG. 11 is a plan view illustrating a portion of a 3D semiconductormemory device according to an exemplary embodiment of the inventiveconcept. FIGS. 12 to 14 are cross-sectional views respectively takenalong lines I-I′, II-II′, and III-III′ of FIG. 11 to illustrate aportion of a 3D semiconductor memory device according to an exemplaryembodiment of the inventive concept.

Referring to FIGS. 10 to 14, a cell array structure CS may be stacked ona peripheral logic structure PS. In other words, the cell arraystructure CS may overlap the peripheral logic structure PS when viewedfrom a plan view.

According to an exemplary embodiment of the inventive concept, theperipheral logic structure PS may include peripheral logic circuits suchas row and column decoders (2 and 4 of FIG. 1), a page buffer (3 of FIG.1), and control circuits (5 of FIG. 1). The peripheral logic circuitsmay be integrated on an entire top surface of a semiconductor substrate10. In addition, the peripheral logic structure PS may further include alower interconnection structure electrically connected to the peripherallogic circuits and a lower insulation layer 50 covering the peripherallogic circuits and the lower interconnection structure.

According to an exemplary embodiment of the inventive concept, theperipheral logic structure PS may include first and secondmetal-oxide-semiconductor (MOS) transistors TR1 and TR2 included in apage buffer 20, a third MOS transistor TR3 included in a voltagegenerator 30, and a fourth MOS transistor TR4 included in a row decoder40.

The first MOS transistor TR1 may be formed on a first well region 21 nthat is formed by doping a portion of the semiconductor substrate 10with N-type dopants. The second MOS transistor TR2 may be formed on asecond well region 21 p that is formed by doping a portion of thesemiconductor substrate 10 with P-type dopants. The third MOS transistorTR3 may be formed on a third well region 31 that is formed by doping aportion of the semiconductor substrate 10 with N-type or P-type dopants.The fourth MOS transistor TR4 may be formed on a fourth well region 39that is formed by doping a portion of the semiconductor substrate 10with N-type or P-type dopants. Active regions may be defined in thefirst to fourth well regions 21 n, 21 p, 31, and 39 by a deviceisolation layer 11, respectively. In addition, contact plugs andinterconnections that are electrically connected to the lowerinterconnection structure may be connected to the first to fourth MOStransistors TR1, TR2, TR3, and TR4. For example, such connections may bemade to source and/or drain electrodes of the first to fourth MOStransistors TR1, TR2, TR3, and TR4. In detail, as shown in FIG. 12, MOStransistor TR3 may be connected to a linking interconnection 41 via twocontact plugs and an interconnection disposed between the two contactplugs.

According to an exemplary embodiment of the inventive concept, the lowerinterconnection structure may be disposed between the cell arraystructure CS and the peripheral logic circuits in a vertical view. Thelower interconnection structure may include first lower interconnections43, the linking interconnection 41, and second lower interconnections45. The first lower interconnections 43 may be electrically connected tothe page buffer 20. The linking interconnection 41 and the second lowerinterconnections 45 may be electrically connected to the voltagegenerator 30. In addition, one or more well contact plugs WCP may beconnected to the second lower interconnections 45. Top surfaces of thewell contact plugs WCP may be substantially coplanar with a top surfaceof the lower insulation layer 50.

According to an exemplary embodiment of the inventive concept, the cellarray structure CS may include a well plate electrode 60, asemiconductor layer 70 covering the well plate electrode 60, stackstructures ST disposed on the semiconductor layer 70, and verticalstructures VS penetrating each of the stack structures ST. Each of thestack structures ST may include electrodes EL vertically stacked on thesemiconductor layer 70.

The well plate electrode 60 may be disposed on the top surface of thelower insulation layer 50 and may be in contact with the top surfaces ofthe well contact plugs WCP. In an exemplary embodiment of the inventiveconcept, the well plate electrode 60 may have a plate shape and may beelectrically connected to the voltage generator 30 through the secondlower interconnections 45 and the linking interconnection 41. The wellplate electrode 60 may include a metal (e.g., tungsten, copper, oraluminum), a conductive metal nitride (e.g., titanium nitride ortantalum nitride), a transition metal (e.g., titanium or tantalum), or ametal silicide. In an exemplary embodiment of the inventive concept, thewell plate electrode 60 may be formed of the conductive metal nitride,and a thickness of the well plate electrode 60 may be less than that ofthe first and second lower interconnections 43 and 45.

In an exemplary embodiment of the inventive concept, the well plateelectrode 60 may overlap the second lower interconnections 45 whenviewed from a plan view. Since the well plate electrode 60 has the plateshape, positions or arrangements of the well contact plugs WCP, thesecond lower interconnections 45, the linking interconnection 41, andthe voltage generator 30 may be variously changed. This will bedescribed later in more detail.

The semiconductor layer 70 may be in direct contact with a top surfaceof the well plate electrode 60. In an exemplary embodiment of theinventive concept, an area of the semiconductor layer 70 may besubstantially equal to an area of the well plate electrode 60. Thesemiconductor layer 70 may include silicon (Si), germanium (Ge), or amixture thereof. The semiconductor layer 70 may be formed of asemiconductor material doped with dopants having a first conductivitytype or an intrinsic semiconductor material not doped with dopants. Inaddition, the semiconductor layer 70 may have a single-crystallinestructure, an amorphous structure, or a poly-crystalline structure. Inan exemplary embodiment of the inventive concept, the semiconductorlayer 70 may include a cell array region CAR and a contact region CTRdisposed around the cell array region CAR.

According to an exemplary embodiment of the inventive concept, a wellconductive layer and a poly-silicon layer may be sequentially depositedon the lower insulation layer 50, and the poly-silicon layer and thewell conductive layer may be patterned to form the well plate electrode60 and the semiconductor layer 70. In an exemplary embodiment of theinventive concept, the poly-silicon layer may be doped with dopantshaving the first conductivity type during the process of depositing thepoly-silicon layer. In an exemplary embodiment of the inventive concept,after an undoped poly-silicon layer is deposited, a lower portion of thesemiconductor layer 70 may be doped with dopants having the firstconductivity type to form a well dopant region. In an exemplaryembodiment of the inventive concept, after the deposition of thepoly-silicon layer, a laser annealing process may be performed to reducea grain boundary of the poly-silicon layer.

According to an exemplary embodiment of the inventive concept, the stackstructures ST may extend in parallel to each other in a first directionD1 on the semiconductor layer 70 and may be spaced apart from each otherin a second direction D2. Each of the stack structures ST may includethe electrodes EL and insulating layers ILD that are alternately andrepeatedly stacked on the semiconductor layer 70. The electrodes EL ofthe stack structures ST may include a conductive material. For example,the electrodes EL may include a doped semiconductor material (e.g.,doped silicon), a metal (e.g., tungsten, copper, or aluminum), aconductive metal nitride (e.g., titanium nitride or tantalum nitride),or a transition metal (e.g., titanium or tantalum). Thicknesses of theinsulating layers ILD of the stack structures ST may be varied dependingon characteristics of the 3D semiconductor memory device. For example,the thickness of the lowermost insulating layer ILD may be smaller thanthat of each of other insulating layers ILD. In addition, one or some ofthe insulating layers ILD may be thicker than other insulating layersILD. The insulating layers ILD may include silicon oxide.

Each of the stack structures ST may have a stepwise structure in thecontact region CTR to electrically connect the electrodes EL to theperipheral logic circuits. In other words, each of the stack structuresST may have a sloped profile in the contact region CTR.

An upper insulation layer 80 having a planarized top surface may bedisposed on the semiconductor layer 70 to cover end portions of theelectrodes EL which constitute the stepwise structure. In addition, acapping insulation layer 90 may cover a plurality of the stackstructures ST and the upper insulation layer 80.

Bit lines BL may be disposed on the capping insulation layer 90 to crossover the stack structures ST. The bit lines BL may extend in the seconddirection D2. The bit lines BL may be electrically connected to thevertical structures VS through bit line contact plugs BPLG. In addition,the bit lines BL may be electrically connected to the first lowerinterconnections 43 of the peripheral logic structure PS.

According to an exemplary embodiment of the inventive concept, thevertical structures VS may be disposed in the cell array region CAR andmay penetrate the stack structures ST to be connected to thesemiconductor layer 70. In an exemplary embodiment of the inventiveconcept, the vertical structures VS may be arranged in a zigzag formalong one direction when viewed from a plan view. In an exemplaryembodiment of the inventive concept, the vertical structures VS may bearranged in a line along one direction when viewed from a plan view. Inan exemplary embodiment of the inventive concept, the verticalstructures VS may include a semiconductor material. Bottom surfaces ofthe vertical structures VS may be disposed at a level between the topsurface and the bottom surface of the semiconductor layer 70. Each ofthe vertical structures VS may include a contact pad connected to thebit line contact plug BPLG. The contact pad may correspond to a top endportion of the vertical structure VS.

According to an exemplary embodiment of the inventive concept, a datastorage layer DS may be disposed between the stack structure ST and thevertical structure VS. In an exemplary embodiment of the inventiveconcept, the data storage layer DS may include a charge storage layer.For example, the data storage layer DS may include a trap insulatinglayer, a floating gate electrode, or an insulating layer includingconductive nano dots. Data stored in the data storage layer DS may bechanged using Fowler-Nordheim tunneling that is caused by a voltagedifference between the electrode EL and the vertical structure VSincluding the semiconductor material. In an exemplary embodiment of theinventive concept, the data storage layer DS may include a thin layercapable of storing data on the basis of another operation principle. Forexample, the data storage layer DS may include a thin layer used in aphase-change memory or a thin layer used in a variable resistancememory.

In an exemplary embodiment of the inventive concept, each of commonsource regions 71 may be disposed in the semiconductor layer 70 betweenthe stack structures ST adjacent to each other. The common sourceregions 71 may extend in parallel to the stack structures ST along thefirst direction D1. In an exemplary embodiment of the inventive concept,the common source regions 71 may be formed by injecting dopants having asecond conductivity type into the semiconductor layer 70. In anexemplary embodiment of the inventive concept, bottom surfaces of thecommon source regions 71 may be spaced apart from the top surface of thewell plate electrode 60.

According to an exemplary embodiment of the inventive concept, a commonsource plug CSPLG may be connected to each of the common source regions71. A sidewall insulating spacer SP may be disposed between the commonsource plug CSPLG and the stack structure ST. A ground voltage may beapplied to the common source regions 71 through the common source plugsCSPLG during a read or program operation of the 3D semiconductor memorydevice. In an exemplary embodiment of the inventive concept, the commonsource plugs CSPLG may have substantially uniform widths and may extendin parallel to each other along the first direction D1. The sidewallinsulating spacers SP may be opposite to each other between the stackstructures ST adjacent to each other. In an exemplary embodiment of theinventive concept, the sidewall insulating spacer SP may fill a spacebetween the stack structures ST adjacent to each other, and the commonsource plug CSPLG may penetrate the sidewall insulating spacer SP to belocally connected to the common source region 71.

An interconnecting structure that electrically connects the cell arraystructure CS to the peripheral logic structure PS may be disposed on endportions, having the stepwise structures, of the stack structures ST. Inan exemplary embodiment of the inventive concept, the interconnectingstructure may include contact plugs PLG penetrating the upper insulationlayer 80 to be respectively connected to the end portions of theelectrodes EL, upper interconnections UCL disposed on the cappinginsulation layer 90 and connected to the contact plugs PLG throughcontact patterns CT, one or more connection plugs WPLG penetrating thecapping insulation layer 90 and the upper and lower insulation layers 80and 50, and interconnection lines CL connecting the interconnectionplugs WPLG to the upper interconnections UCL.

The contact plugs PLG disposed in the contact region CTR may havevertical lengths different from each other. Top surfaces of the contactplugs PLG may be substantially coplanar with the top surfaces of thevertical structures VS.

In an exemplary embodiment of the inventive concept, the stack structureST and the peripheral logic structure PS may be electrically connectedto each other through the interconnection plug WPLG. The interconnectionplug WPLG may penetrate the capping insulating layer 90 and the upperand lower insulation layers 80 and 50 to be electrically connected tothe peripheral logic circuit(s). For example, the interconnection plugWPLG may be electrically connected to the row decoder 40 (e.g., a wordline driver).

During the erase operation of the 3D semiconductor memory device, theerase voltage may be provided to the semiconductor layer 70 and thevertical structures VS through the well plate electrode 60. At thistime, the erase voltage may be uniformly provided to the semiconductorlayer 70 through the well plate electrode 60 having the plate shape.Thus, a time for providing the erase voltage to the two-dimensionallyarranged vertical structures VS may be substantially uniform. In otherwords, the erase voltage can be prevented from being varied according topositions of the vertical structures VS.

In an exemplary embodiment of the inventive concept, a vertical distancebetween the well plate electrode 60 and the voltage generator 30 may beless than a height of the cell array structure CS. Thus, a transmittingpath of the erase voltage from the voltage generator 30 to the wellplate electrode 60 may be reduced. In other words, a voltage drop of theerase voltage may be reduced during the erase operation of the 3Dsemiconductor memory device.

FIGS. 15A, 15B, 15C, and 15D are enlarged views of a portion ‘A’ of FIG.12, according to an exemplary embodiment of the inventive concept.

According to an exemplary embodiment of the inventive concept, the 3Dsemiconductor memory device may be an NAND flash memory device. Forexample, the data storage layer DS disposed between the stack structureST and the vertical structure VS may include a tunnel dielectric layerTIL, a charge storage layer CIL, and a blocking dielectric layer BLK.Data stored in the data storage layer DS may be changed usingFowler-Nordheim tunneling caused by the voltage difference between theelectrode EL and the vertical structure VS including the semiconductormaterial.

According to an exemplary embodiment of the inventive conceptillustrated in FIG. 15A, the tunnel dielectric layer TIL, the chargestorage layer CIL, and the blocking dielectric layer BLK may extend frombetween the vertical structure VS and the electrode EL to between thevertical structure VS and the insulating layer ILD.

According to an exemplary embodiment of the inventive conceptillustrated in FIG. 15B, the tunnel dielectric layer TIL and the chargestorage layer CIL may extend from between the vertical structure VS andthe electrode EL to between the vertical structure VS and the insulatinglayer ILD. The blocking dielectric layer BLK may extend from between thevertical structure VS and the electrode EL onto a top surface and abottom surface of the electrode EL. In other words, the blockingdielectric layer BLK may be disposed between the electrode EL and theinsulating layer ILD adjacent to each other.

According to an exemplary embodiment of the inventive conceptillustrated in FIG. 15C, the tunnel dielectric layer TIL may extend frombetween the vertical structure VS and the electrode EL to between thevertical structure VS and the insulating layer ILD. The charge storagelayer CIL and the blocking insulating layer BLK may extend from betweenthe vertical structure VS and the electrode EL onto the top surface andthe bottom surface of the electrode EL. In other words, the chargestorage layer CIL and the blocking insulating layer BLK may be disposedbetween the electrode EL and the insulating layer ILD adjacent to eachother.

According to an exemplary embodiment of the inventive conceptillustrated in FIG. 15D, the tunnel dielectric layer TIL, the chargestorage layer CIL, and the blocking dielectric layer BLK may extend frombetween the vertical structure VS and the electrode EL onto the topsurface and the bottom surface of the electrode EL. In other words, thetunnel dielectric layer TIL, the charge storage layer CIL, and theblocking dielectric layer BLK may be disposed between the electrode ELand the insulating layer ILD adjacent to each other.

The charge storage layer CIL of the data storage layer DS may includetrap site-rich insulating layers or insulating layers including nanoparticles. The charge storage layer CIL may be formed using a chemicalvapor deposition (CVD) technique or an atomic layer deposition (ALD)technique. For example, the charge storage layer CIL may include a trapinsulating layer, a floating gate electrode, or an insulating layerincluding conductive nano dots. In an exemplary embodiment of theinventive concept, the charge storage layer CIL may include a siliconnitride layer, a silicon oxynitride layer, a silicon-rich nitride layer,a nano-crystalline silicon layer, or a laminated trap layer.

The tunnel dielectric layer TIL may include a material having an energyband gap greater than that of the charge storage layer CIL and may beformed by a CVD technique or an ALD technique. For example, the tunneldielectric layer TIL may include a silicon oxide layer formed by the CVDtechnique or the ALD technique. In addition, a thermal treatment processmay be performed on the tunnel dielectric layer TIL deposited by the CVDor ALD technique. The thermal treatment process may be a rapid thermalnitridation (RTN) process or an annealing process performed in anatmosphere including nitrogen or oxygen.

The blocking dielectric layer BLK may include first and second blockingdielectric layers that are formed of different materials from eachother. One of the first and second blocking dielectric layers mayinclude a material of which an energy band gap is smaller than that ofthe tunnel dielectric layer TIL and greater than that of the chargestorage layer CIL. Each of the first and second blocking dielectriclayers may be formed by a CVD technique or an ALD technique. At leastone of the first and second blocking dielectric layers may be formed bya wet oxidation process. In an exemplary embodiment of the inventiveconcept, the first blocking dielectric layer may include a high-kdielectric layer such as an aluminum oxide layer or a hafnium oxidelayer, and the second blocking dielectric layer may include a materialof which a dielectric constant is lower than that of the first blockingdielectric layer. In an exemplary embodiment of the inventive concept,the second blocking dielectric layer may include at least one of theaforementioned high-k dielectric layers, and the first blockingdielectric layer may include a material of which a dielectric constantis lower than that of the second blocking dielectric layer.

FIGS. 16A and 16B are enlarged views of a portion ‘B’ of FIG. 13,according to an exemplary embodiment of the inventive concept.

Referring to FIGS. 16A and 16B, the vertical structure VS may include afirst semiconductor pattern SP1 connected to the semiconductor layer 70and a second semiconductor pattern SP2 disposed between the firstsemiconductor pattern SP1 and the data storage layer DS. The first andsecond semiconductor patterns SP1 and SP2 may include a semiconductormaterial. In an exemplary embodiment of the inventive concept, the firstsemiconductor pattern SP1 may have a circular pillar shape. In anexemplary embodiment of the inventive concept, the first semiconductorpattern SP1 may have a hollow pipe shape or a hollow macaroni shape. Inthis case, the first semiconductor pattern SP1 may have a closed bottomend and an inside of the first semiconductor pattern SP1 may be filledwith an insulating material.

The data storage layer DS may be disposed between the vertical structureVS and the stack structure ST. The data storage layer DS may include avertical pattern VP penetrating the stack structure ST and a horizontalpattern HP extending from between the vertical pattern VP and theelectrode EL onto the top surface and the bottom surface of theelectrode EL.

The common source region 71 formed in the semiconductor layer 70 mayinclude dopants having the second conductivity type and may be spacedapart from the top surface of the well plate electrode 60. According toan exemplary embodiment of the inventive concept illustrated in FIG.16B, the semiconductor layer 70 may include a well dopant region 70 wthat has the first conductivity type and is in contact with the wellplate electrode 60. The well dopant region 70 w may be heavily doped toreduce an ohmic resistance between the well plate electrode 60 and thesemiconductor layer 70. The common source region 71 having the secondconductivity type may be spaced apart from the well dopant region 70 w.

The well plate electrode 60 may be thinner than the semiconductor layer70 and may be connected to the well contact plug WCP. In an exemplaryembodiment of the inventive concept, the well contact plug WCP mayinclude a barrier metal layer M1 and a metal layer M2. The well plateelectrode 60 may be formed of the same material as the barrier metallayer M1. For example, the barrier metal layer M1 may include tantalum(Ta), tantalum nitride (TaN), tantalum-silicon nitride (TaSiN), titanium(Ti), titanium nitride (TiN), titanium-silicon nitride (TiSiN), tungsten(W), or tungsten nitride (WN). The metal layer M2 may include tungsten(W), aluminum (Al), copper (Cu), or a copper alloy. In other words, inan exemplary embodiment of the inventive concept, the well plateelectrode 60 may be formed of the same material as the barrier metallayer M1 of which an electrical conductivity is lower than that of themetal layer M2. Thus, a contact resistance between the well plateelectrode 60 and the semiconductor layer 70 may be reduced as well as areactivity between the well plate electrode 60 and the semiconductorlayer 70.

FIGS. 17A, 17B, and 17C are perspective views each illustratingperipheral logic structures of 3D semiconductor memory devices accordingto an exemplary embodiment of the inventive concept.

A peripheral logic structure PS may include peripheral logic circuitsintegrated on a semiconductor substrate 10, a lower interconnectionstructure electrically connected to the peripheral logic circuits, and alower insulation layer 50 covering the peripheral logic circuits and thelower interconnection structure.

According to an exemplary embodiment of the inventive conceptillustrated in FIG. 17A, the lower interconnection structure may includefirst lower interconnections 43 electrically connected to the pagebuffer 20, a linking interconnection 41 electrically connected to thevoltage generator 30, and second lower interconnections 45.

The first lower interconnections 43 and the second lowerinterconnections 45 may extend in parallel to each other along onedirection and may be disposed at the same level from a top surface ofthe semiconductor substrate 10. Positions of the second lowerinterconnections 45 may be freely changed under the well plate electrode60.

In an exemplary embodiment of the inventive concept, the first lowerinterconnections 43 may be arranged between the second lowerinterconnections 45 spaced apart from each other. The second lowerinterconnections 45 spaced apart from each other may be connected incommon to the linking interconnection 41 through contact plugs, and thelinking interconnection 41 may be electrically connected to the voltagegenerator 30 through a contact plug. The well contact plugs WCP may beconnected to top surfaces of the second lower interconnections 45 andmay also be connected to the well plate electrode 60 having the plateshape.

The number of the second lower interconnections 45 is two in FIG. 17A.However, the inventive concept is not limited thereto. In an exemplaryembodiment of the inventive concept, the number of the second lowerinterconnections 45 may be greater than two, and the linkinginterconnection 41 may be provided in plural.

According to an exemplary embodiment of the inventive conceptillustrated in FIG. 17B, a lower interconnection structure may includefirst lower interconnections 43 electrically connected to the pagebuffer 20 and a second lower interconnection 45 electrically connectedto the voltage generator 30. The first lower interconnections 43 and thesecond lower interconnection 45 may extend in parallel to each otheralong one direction and may be disposed at the same level from the topsurface of the semiconductor substrate 10. In the present embodiment,the second lower interconnection 45 may be directly connected to thevoltage generator 30 through a contact plug. In other words, the linkinginterconnection 41 of FIG. 17A may be omitted in the present embodiment.A position of the second lower interconnection 45 may be freely changedunder the well plate electrode 60. The well contact plugs WCP may beconnected to the top surface of the second lower interconnection 45 andmay also be connected to the well plate electrode 60 having the plateshape. In the present embodiment, the well plate electrode 60 may beelectrically connected to the voltage generator 30 through one secondlower interconnection 45.

According to an exemplary embodiment of the inventive conceptillustrated in FIG. 17C, the well plate electrode 60 may be directlyconnected to the voltage generator 30 through the well contact plug WCP.In other words, the linking interconnection 41 and the second lowerinterconnection 45 of FIG. 17A may be omitted in the present embodiment.Since the well plate electrode 60 has the plate shape in the presentembodiment, positions of the well contact plug WCP and voltage generator30 may be freely changed under the well plate electrode 60.

FIGS. 18A and 18B each illustrate a well plate electrode included in a3D semiconductor memory device according to an exemplary embodiment ofthe inventive concept.

Referring to FIGS. 18A and 18B, a well plate electrode 60 may bedisposed on the bottom surface of the semiconductor layer 70, andelectrodes EL may be vertically stacked on the top surface of thesemiconductor layer 70. An area of the lowermost electrode EL may besubstantially equal to an area of the semiconductor layer 70. Areas ofthe electrodes EL may decrease as a distance from the top surface of thesemiconductor layer 70 increases.

In the embodiments illustrated in FIGS. 18A and 18B, the well plateelectrode 60 may be in contact with a portion of the semiconductor layer70. For example, as illustrated in FIG. 18A, the well plate electrode 60may have a line shape that intersects a central portion of thesemiconductor layer 70. Additionally, the well plate electrode 60 mayhave an island shape that overlaps a central portion of thesemiconductor layer 70, as illustrated in FIG. 18B.

FIGS. 19 and 20 are cross-sectional views respectively taken along linesI-I′ and II-II′ of FIG. 11 to illustrate a 3D semiconductor memorydevice according to an exemplary embodiment of the inventive concept.FIG. 21 is an enlarged view of a portion ‘B’ of FIG. 20, according to anexemplary embodiment of the inventive concept.

Referring to FIGS. 19 and 20, a cell array structure CS may be stackedon a peripheral logic structure PS. In other words, the cell arraystructure CS may overlap the peripheral logic structure PS when viewedfrom a plan view.

As described above, the peripheral logic structure PS may include theperipheral logic circuits such as the row and column decoders (2 and 4of FIG. 1), the page buffer (3 of FIG. 1), and the control circuits (5of FIG. 1). The peripheral logic circuits may be integrated on an entiretop surface of a semiconductor substrate 10. In addition, the peripherallogic structure PS may further include a lower interconnection structureelectrically connected to the peripheral logic circuits and a lowerinsulation layer 50 covering the peripheral logic circuits and the lowerinterconnection structure.

According to an exemplary embodiment of the inventive concept, the lowerinterconnection structure may be disposed between the cell arraystructure CS and the peripheral logic circuits in a vertical view. Thelower interconnection structure may include first lower interconnections43, a linking interconnection 41, and second lower interconnections 45.The first lower interconnections 43 may be electrically connected to thepage buffer 20. The linking interconnection 41 and the second lowerinterconnections 45 may be electrically connected to the voltagegenerator 30. In addition, one or more well contact plugs WCP may beconnected to the second lower interconnections 45. Top surfaces of thewell contact plugs WCP may be substantially coplanar with the topsurface of the lower insulation layer 50.

According to an exemplary embodiment of the inventive concept, the cellarray structure CS may include a well plate electrode 60, asemiconductor layer 70 covering the well plate electrode 60, stackstructures ST disposed on the semiconductor layer 70, and verticalstructures VS penetrating each of the stack structures ST. Each of thestack structures ST may include electrodes EL vertically stacked on thesemiconductor layer 70.

As described above, the well plate electrode 60 may be disposed on thetop surface of the lower insulation layer 50 and may be in contact withthe top surfaces of the well contact plugs WCP. In an exemplaryembodiment of the inventive concept, the well plate electrode 60 mayhave a plate shape. The well plate electrode 60 may be electricallyconnected to the voltage generator 30 through the second lowerinterconnections 45 and the linking interconnection 41.

The semiconductor layer 70 may be in direct contact with the top surfaceof the well plate electrode 60. In an exemplary embodiment of theinventive concept, an area of the semiconductor layer 70 may besubstantially equal to an area of the well plate electrode 60.

The stack structures ST may extend in parallel to each other in a firstdirection D1 on the semiconductor layer 70 and may be spaced apart fromeach other in a second direction D2. Each of the stack structures ST mayinclude the electrodes EL and insulating layers ILD which arealternately and repeatedly stacked on the semiconductor layer 70.

According to the present embodiment, each of the vertical structures VSmay include a lower semiconductor pattern LSP penetrating a lowerportion of the stack structure ST and an upper semiconductor pattern USPpenetrating an upper portion of the stack structure ST. The lowersemiconductor pattern LSP may be connected to the semiconductor layer70, and the upper semiconductor pattern USP may be connected to thelower semiconductor pattern LSP. In the present embodiment, the verticalpattern VP of the data storage layer DS may be disposed between theupper semiconductor pattern USP and the stack structure ST, asillustrated in FIG. 21.

According to an exemplary embodiment of the inventive concept, the uppersemiconductor pattern USP may have a hollow pipe shape or a hollowmacaroni shape. Here, a bottom end of the upper semiconductor patternUSP may be closed, and an inside of the upper semiconductor pattern USPmay be filled with an insulating pattern. In addition, a bottom surfaceof the upper semiconductor pattern USP may be lower than a topmostportion of a top surface of the lower semiconductor pattern LSP. Inother words, a portion of the top surface of the lower semiconductorpattern LSP may be recessed, and a bottom end portion of the uppersemiconductor pattern USP may be inserted into the recessed region ofthe top surface of the lower semiconductor pattern LSP. The uppersemiconductor pattern USP may be formed of a semiconductor material. Forexample, the upper semiconductor pattern USP may include silicon (Si),germanium (Ge), or a mixture thereof. The upper semiconductor patternUSP may be formed of a semiconductor material doped with dopants or anintrinsic semiconductor material not doped with dopants. The uppersemiconductor pattern USP may have a single-crystalline structure, anamorphous structure, or a poly-crystalline structure. In addition, theupper semiconductor pattern USP may have a conductive pad correspondingto its top end portion. The conductive pad may be a dopant region dopedwith dopants or may be formed of a conductive material.

In more detail, the upper semiconductor pattern USP may include a firstsemiconductor pattern SP1 and a second semiconductor pattern SP2, asillustrated in FIG. 21. The first semiconductor pattern SP1 may beconnected to the lower semiconductor pattern LSP and may have a pipe ormacaroni shape having a closed bottom end. The inside of the firstsemiconductor pattern SP1 may be filled with an insulating pattern. Thefirst semiconductor pattern SP1 may be in contact with an inner sidewallof the second semiconductor pattern SP2 and the top surface of the lowersemiconductor pattern LSP. In other words, the first semiconductorpattern SP1 may electrically connect the second semiconductor patternSP2 to the lower semiconductor pattern LSP. The second semiconductorpattern SP2 may cover an inner sidewall of the stack structure ST. Thesecond semiconductor pattern SP2 may have a pipe or macaroni shape ofwhich top and bottom ends are opened. The second semiconductor patternSP2 may not be in contact with the lower semiconductor pattern LSP butmay be spaced apart from the lower semiconductor pattern LSP. The firstand second semiconductor patterns SP1 and SP2 may be undoped or may bedoped with dopants having the same conductivity type as thesemiconductor layer 70. The first and second semiconductor patterns SP1and SP2 may be in a poly-crystalline state or a single-crystallinestate.

According to an exemplary embodiment of the inventive concept, the lowersemiconductor pattern LSP may be used as a channel region of the groundselection transistor GST described with reference to FIG. 3. The lowersemiconductor pattern LSP may be formed of a semiconductor materialhaving the same conductivity type as the semiconductor layer 70. In anexemplary embodiment of the inventive concept, the lower semiconductorpattern LSP may be an epitaxial pattern that is formed by an epitaxialtechnique or a laser crystallization technique which uses thesemiconductor layer 70 as a seed. In this case, the lower semiconductorpattern LSP may have a single-crystalline structure or may have apoly-crystalline structure of which a grain size is greater than that ofa semiconductor material formed by a CVD technique. In an exemplaryembodiment of the inventive concept, the lower semiconductor pattern LSPmay be formed of a poly-crystalline semiconductor material (e.g.,poly-crystalline silicon). According to an exemplary embodiment of theinventive concept, the insulating layer ILD adjacent to the lowersemiconductor pattern LSP may be in direct contact with a sidewall ofthe lower semiconductor pattern LSP.

In an exemplary embodiment of the inventive concept, the lowersemiconductor pattern LSP may have a pillar shape penetrating thelowermost electrode EL, as illustrated in FIG. 21. A bottom surface ofthe lower semiconductor pattern LSP may be lower than the top surface ofthe semiconductor layer 70 and may be spaced apart from the well plateelectrode 60. The top surface of the lower semiconductor pattern LSP maybe higher than a top surface of the lowermost electrode EL.

FIG. 22 is a view illustrating an erasing operation of a 3Dsemiconductor memory device according to an exemplary embodiment of theinventive concept. The 3D semiconductor memory device according to thepresent embodiment may be a NAND flash memory device like that describedwith reference to FIG. 3.

Referring to FIG. 22, during the erase operation of the NAND flashmemory device, a voltage difference may be provided between the verticalstructure VS including the semiconductor material and the word line todischarge charges stored in the data storage layer DS to the verticalstructure VS.

An erase voltage V_(ERS) generated from the voltage generator 30 may beapplied to the well plate electrode 60 during the erase operation. Forexample, the erase voltage V_(ERS) may be in a range of 10V to 20V. Aground voltage Vss may be applied to the word lines WL. The groundselection line GSL, the string selection line SSL, the bit line BL, andthe common source plug CSPLG may be floated during the erase operation.

Under the voltage conditions described above, the erase voltage V_(ERS)applied to the well plate electrode 60 may be transmitted to thesemiconductor layer 70 and the vertical structure VS including thesemiconductor material. Thus, a large voltage difference may be providedbetween the vertical structure VS and the word lines WL to discharge thecharges stored in the data storage layer DS to the vertical structure VSby Fowler-Nordheim tunneling. According to an exemplary embodiment ofthe inventive concept, since the erase voltage V_(ERS) may be applied tothe entire bottom surface of the semiconductor layer 70 through the wellplate electrode 60, a difference between the erase voltage V_(ERS)transmitted to the vertical structure VS disposed in a central region ofthe cell array structure CS and the erase voltage V_(ERS) transmitted tothe vertical structure VS disposed in an edge region of the cell arraystructure CS can be reduced or minimized.

FIG. 23 is a block diagram illustrating an electronic system including a3D semiconductor memory device according to an exemplary embodiment ofthe inventive concept.

Referring to FIG. 23, an electronic system 1100 may be applied to apersonal digital assistant (PDA), a portable computer, a web tablet, awireless phone, a mobile phone, a digital music player, a memory card,or other electronic products for receiving and/or transmittinginformation data wirelessly.

The electronic system 1100 may include a controller 1110, aninput/output (I/O) unit 1120, a memory device 1130, an interface unit1140, and a data bus 1150. At least two of the controller 1110, the I/Ounit 1120, the memory device 1130, and the interface unit 1140 maycommunicate with each other through the data bus 1150.

The controller 1110 may include at least one of a microprocessor, adigital signal processor, a microcontroller, or other logic deviceshaving a similar function to any one thereof. The memory device 1130 maystore data and/or commands executed by the controller 1110. The I/O unit1120 may receive data or signals from the outside or may output data orsignals to the outside. For example, the I/O unit 1120 may include akeypad, a keyboard and/or a display device.

The memory device 1130 may include a 3D semiconductor memory deviceaccording to an exemplary embodiment of the inventive concept. Inaddition, the memory device 1130 may further include another type ofmemory device or a random access non-volatile memory device.

The interface unit 1140 may transmit electrical data to a communicationnetwork and/or may receive electrical data from a communication network.

FIG. 24 is a block diagram illustrating a memory card including a 3Dsemiconductor memory device according to an exemplary embodiment of theinventive concept.

Referring to FIG. 24, a memory card 1200 used for storing data mayinclude a memory device 1210 implemented with a 3D semiconductor memorydevice according to an exemplary embodiment of the inventive concept.The memory card 1200 may include a memory controller 1220 that controlsdata communication between a host and the memory device 1210.

A static random access memory (SRAM) device 1221 may be used as aworking memory of a central processing unit (CPU) 1222. A host interfaceunit 1223 may be configured to include a data communication protocolbetween the memory card 1200 and the host. An error check and correction(ECC) block 1224 may detect and correct errors of data which are readout from the memory device 1210. A memory interface unit 1225 mayinterface with the memory device 1210. The CPU 1222 may control overalloperations for data communication of the memory controller 1220. Thememory card 1200 may further include a read only memory (ROM) devicethat stores code data used for interfacing with the host.

FIG. 25 is a block diagram illustrating an information processing systemincluding a 3D semiconductor memory device according to an exemplaryembodiment of the inventive concept.

Referring to FIG. 25, a memory system 1310 may be installed in aninformation processing system 1300 such as a mobile device or a desktopcomputer. The information processing system 1300 may include a modem1320, a CPU 1330, a RAM 1340, and a user interface unit 1350 that areelectrically connected to the memory system 1310 through a system bus1360. The memory system 1310 may have the substantially same structureas the memory card 1200 described with reference to FIG. 24. In otherwords, the memory system 1310 may include a memory device 1311 and amemory controller 1312. The memory system 1310 may store data processedby the CPU 1330 or data inputted from an external system. In anexemplary embodiment of the inventive concept, the memory system 1310may be a solid state disk (SSD). In this case, the informationprocessing system 1300 may stably store data in the memory system 1310.In addition, as reliability of the memory system 1310 increases, thememory system 1310 may reduce a resource consumed for correcting errors.Thus, the information processing system 1300 may perform a fast dataexchange function. The information processing system 1300 may furtherinclude an application chipset, a camera image processor (CIS), and/oran input/output (I/O) unit.

The 3D semiconductor memory devices and/or the memory system describedabove may be encapsulated using various packaging techniques. Forexample, the 3D semiconductor memory devices and/or the memory systemaccording to the aforementioned exemplary embodiments of the inventiveconcept may be encapsulated using any one of a package on package (POP)technique, a ball grid arrays (BGAs) technique, a chip scale packages(CSPs) technique, a plastic leaded chip carrier (PLCC) technique, aplastic dual in-line package (PDIP) technique, a die in waffle packtechnique, a die in wafer form technique, a chip on board (COB)technique, a ceramic dual in-line package (CERDIP) technique, a plasticmetric quad flat package (PMQFP) technique, a plastic quad flat package(PQFP) technique, a small outline package (SOP) technique, a shrinksmall outline package (SSOP) technique, a thin small outline package(TSOP) technique, a thin quad flat package (TQFP) technique, a system inpackage (SIP) technique, a multi-chip package (MCP) technique, awafer-level fabricated package (WFP) technique and a wafer-levelprocessed stack package (WSP) technique.

According to an exemplary embodiment of the inventive concept, a cellarray structure may be formed on a peripheral logic structure. The cellarray structure may include may include a semiconductor layer formed ona top surface of a well plate electrode and memory cellsthree-dimensionally arranged on the semiconductor layer. During theerase operation of the memory cells, an erase voltage may be applied tothe semiconductor layer and the memory cells through the well plateelectrode covering a bottom surface of the semiconductor layer. In otherwords, the erase voltage may be applied to the entire bottom surface ofthe semiconductor layer, such that the voltage drop may be reduced whenthe erase voltage is transmitted to the three-dimensionally arrangedmemory cells.

While the inventive concept has been described with reference toexemplary embodiments thereof, it will be apparent to those skilled inthe art that various changes and modifications may be made theretowithout departing from the scope of the inventive concept as defined bythe following claims and their equivalents.

What is claimed is:
 1. A method of fabricating a three-dimensional (3D)semiconductor memory device, the method comprising: forming a peripherallogic structure comprising peripheral logic circuits on a semiconductorsubstrate; and forming a plurality of memory blocks on the peripherallogic structure to be spaced apart from each other, wherein each of thememory blocks comprises a stack structure including a plurality ofvertically stacked electrodes on a semiconductor layer.
 2. The method ofclaim 1, wherein each of the memory blocks further comprises a wellplate electrode between the peripheral logic structure and thesemiconductor layer.
 3. The method of claim 2, wherein the semiconductorlayer is in contact with the well plate electrode.
 4. The method ofclaim 2, wherein forming the peripheral logic structure comprises:forming a voltage generator on the semiconductor substrate, and formingan insulation layer to cover the voltage generator.
 5. The method ofclaim 4, wherein forming the peripheral logic structure furthercomprises forming an interconnection structure for electricallyconnecting the well plate electrode to the voltage generator.
 6. Themethod of claim 4, wherein the well plate electrode is formed on a topsurface of the insulation layer.
 7. The method of claim 6, wherein thewell plate electrode is formed to overlap with the interconnectionstructure.
 8. The method of claim 1, wherein forming the plurality ofmemory blocks comprises: forming a well conductive layer on theperipheral logic structure and a poly-silicon layer on the wellconductive layer; and patterning the poly-silicon layer and the wellconductive layer to form the semiconductor layers of the memory blocksand well plate electrodes that are respectively between thesemiconductor layers and the peripheral logic structure.
 9. The methodof claim 1, wherein forming the plurality of memory blocks includes:forming a plurality of vertical structures penetrating the stackstructure of each of the memory blocks; and forming a plurality of bitlines crossing the stack structure and electrically connected to thevertical structures.
 10. The method of claim 1, wherein the stackstructure has a stepwise structure defined by end portions of theelectrodes.